from the ERA of Hope meeting I attended--new molecular imaging as accurate, less

[Lani]

costly than MRI

Research presented at the Department of Defense's annual Era of Hope breast cancer meeting indicates that molecular breast imaging (MBI) appears to have comparable sensitivity and specificity to magnetic resonance imaging (MRI) in the detection of breast cancers, but is more cost-effective.

The findings were reported by Dr. Carrie Beth Hruska of the Mayo Clinic in Rochester, Minnesota.

She and her colleagues performed MBI and MRI in 48 women being evaluated for breast cancer, 42 of whom had suspicious areas on previous examination and 6 who were at high risk for breast cancer. A total of 54 cancers were diagnosed in 32 patients.

There were 53 cancers detected by MRI in 31 patients, for a sensitivity of 98%. MBI revealed 51 cancers in 30 patients, for a sensitivity of 94%. One cancer was not detectable on MRI, MBI, mammography or ultrasound.

Sixteen patients were negative for cancer after MRI and MBI. There were nine true negative findings on MRI for a specificity of 56%. Eight were true negative on MBI for a specificity of 50%.

Because the majority of patients in this study had a high suspicion of having breast cancer, this specificity may not necessarily reflect that of a true screening population, Dr. Hruska cautioned.

"The MRI and MBI interpretations were concordant for presence of disease in 47 of the 48 patients," Dr. Hruska reported. In the case with discordance, two cancers detected on MRI were not detected by MBI.

"This was a retrospective look at patients who were not served well by mammography," Dr. Hruska commented in an interview with Reuters Health after her meeting presentation.

"The sensitivity and specificity of MBI were comparable with MRI," she said. "As MRI is being used more and more, cost will become a major factor. MBI costs four-to-six times less than MRI."

One important advantage of MBI over mammography is that it uses only light compression of the breast tissue rather than heavy compression, she continued.

"MBI is available only at the Mayo Clinic right now, but it will become more widely available soon," Dr. Hruska said. "MBI uses Tc99, which is used commonly in cardiac perfusion studies. It has a high affinity for cancer cells."

The technology still needs to be improved and larger studies are needed, but this is a promising, cost-effective method that may be useful for screening of breast cancer, she concluded.